<?php  if (!defined('BASEPATH')) exit('No direct script access allowed');
/**
 * CodeIgniter
 *
 * An open source application development framework for PHP 5.1.6 or newer
 *
 * @package        CodeIgniter
 * @author        ExpressionEngine Dev Team
 * @copyright    Copyright (c) 2008 - 2011, EllisLab, Inc.
 * @license        http://codeigniter.com/user_guide/license.html
 * @link        http://codeigniter.com
 * @since        Version 1.0
 * @filesource
 */

// ------------------------------------------------------------------------

/**
 * Output Class
 *
 * Responsible for sending final output to browser
 *
 * @package        CodeIgniter
 * @subpackage    Libraries
 * @category    Output
 * @author        ExpressionEngine Dev Team
 * @link        http://codeigniter.com/user_guide/libraries/output.html
 */
class CI_Output
{

    /**
     * Current output string
     *
     * @var string
     * @access    protected
     */
    protected $final_output;
    /**
     * Cache expiration time
     *
     * @var int
     * @access    protected
     */
    protected $cache_expiration = 0;
    /**
     * List of server headers
     *
     * @var array
     * @access    protected
     */
    protected $headers = array();
    /**
     * List of mime types
     *
     * @var array
     * @access    protected
     */
    protected $mime_types = array();
    /**
     * Determines wether profiler is enabled
     *
     * @var book
     * @access    protected
     */
    protected $enable_profiler = FALSE;
    /**
     * Determines if output compression is enabled
     *
     * @var bool
     * @access    protected
     */
    protected $_zlib_oc = FALSE;
    /**
     * List of profiler sections
     *
     * @var array
     * @access    protected
     */
    protected $_profiler_sections = array();
    /**
     * Whether or not to parse variables like {elapsed_time} and {memory_usage}
     *
     * @var bool
     * @access    protected
     */
    protected $parse_exec_vars = TRUE;

    /**
     * Constructor
     *
     */
    function __construct()
    {
        $this->_zlib_oc = @ini_get('zlib.output_compression');

        // Get mime types for later
        if (defined('ENVIRONMENT') AND file_exists(APPPATH . 'config/' . ENVIRONMENT . '/mimes.php')) {
            include APPPATH . 'config/' . ENVIRONMENT . '/mimes.php';
        } else {
            include APPPATH . 'config/mimes.php';
        }


        $this->mime_types = $mimes;

        log_message('debug', "Output Class Initialized");
    }

    // --------------------------------------------------------------------

    /**
     * Get Output
     *
     * Returns the current output string
     *
     * @access    public
     * @return    string
     */
    function get_output()
    {
        return $this->final_output;
    }

    // --------------------------------------------------------------------

    /**
     * Set Output
     *
     * Sets the output string
     *
     * @access    public
     * @param    string
     * @return    void
     */
    function set_output($output)
    {
        $this->final_output = $output;

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Append Output
     *
     * Appends data onto the output string
     *
     * @access    public
     * @param    string
     * @return    void
     */
    function append_output($output)
    {
        if ($this->final_output == '') {
            $this->final_output = $output;
        } else {
            $this->final_output .= $output;
        }

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Set Header
     *
     * Lets you set a server header which will be outputted with the final display.
     *
     * Note:  If a file is cached, headers will not be sent.  We need to figure out
     * how to permit header data to be saved with the cache data...
     *
     * @access    public
     * @param    string
     * @param    bool
     * @return    void
     */
    function set_header($header, $replace = TRUE)
    {
        // If zlib.output_compression is enabled it will compress the output,
        // but it will not modify the content-length header to compensate for
        // the reduction, causing the browser to hang waiting for more data.
        // We'll just skip content-length in those cases.

        if ($this->_zlib_oc && strncasecmp($header, 'content-length', 14) == 0) {
            return;
        }

        $this->headers[] = array($header, $replace);

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Set Content Type Header
     *
     * @access    public
     * @param    string    extension of the file we're outputting
     * @return    void
     */
    function set_content_type($mime_type)
    {
        if (strpos($mime_type, '/') === FALSE) {
            $extension = ltrim($mime_type, '.');

            // Is this extension supported?
            if (isset($this->mime_types[$extension])) {
                $mime_type =& $this->mime_types[$extension];

                if (is_array($mime_type)) {
                    $mime_type = current($mime_type);
                }
            }
        }

        $header = 'Content-Type: ' . $mime_type;

        $this->headers[] = array($header, TRUE);

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Set HTTP Status Header
     * moved to Common procedural functions in 1.7.2
     *
     * @access    public
     * @param    int        the status code
     * @param    string
     * @return    void
     */
    function set_status_header($code = 200, $text = '')
    {
        set_status_header($code, $text);

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Enable/disable Profiler
     *
     * @access    public
     * @param    bool
     * @return    void
     */
    function enable_profiler($val = TRUE)
    {
        $this->enable_profiler = (is_bool($val)) ? $val : TRUE;

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Set Profiler Sections
     *
     * Allows override of default / config settings for Profiler section display
     *
     * @access    public
     * @param    array
     * @return    void
     */
    function set_profiler_sections($sections)
    {
        foreach ($sections as $section => $enable) {
            $this->_profiler_sections[$section] = ($enable !== FALSE) ? TRUE : FALSE;
        }

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Set Cache
     *
     * @access    public
     * @param    integer
     * @return    void
     */
    function cache($time)
    {
        $this->cache_expiration = (!is_numeric($time)) ? 0 : $time;

        return $this;
    }

    // --------------------------------------------------------------------

    /**
     * Display Output
     *
     * All "view" data is automatically put into this variable by the controller class:
     *
     * $this->final_output
     *
     * This function sends the finalized output data to the browser along
     * with any server headers and profile data.  It also stops the
     * benchmark timer so the page rendering speed and memory usage can be shown.
     *
     * @access    public
     * @param    string
     * @return    mixed
     */
    function _display($output = '')
    {
        // Note:  We use globals because we can't use $CI =& get_instance()
        // since this function is sometimes called by the caching mechanism,
        // which happens before the CI super object is available.
        global $BM, $CFG;

        // Grab the super object if we can.
        if (class_exists('CI_Controller')) {
            $CI =& get_instance();
        }

        // --------------------------------------------------------------------

        // Set the output data
        if ($output == '') {
            $output =& $this->final_output;
        }

        // --------------------------------------------------------------------

        // Do we need to write a cache file?  Only if the controller does not have its
        // own _output() method and we are not dealing with a cache file, which we
        // can determine by the existence of the $CI object above
        if ($this->cache_expiration > 0 && isset($CI) && !method_exists($CI, '_output')) {
            $this->_write_cache($output);
        }

        // --------------------------------------------------------------------

        // Parse out the elapsed time and memory usage,
        // then swap the pseudo-variables with the data

        $elapsed = $BM->elapsed_time('total_execution_time_start', 'total_execution_time_end');

        if ($this->parse_exec_vars === TRUE) {
            $memory = (!function_exists('memory_get_usage')) ? '0' : round(memory_get_usage() / 1024 / 1024, 2) . 'MB';

            $output = str_replace('{elapsed_time}', $elapsed, $output);
            $output = str_replace('{memory_usage}', $memory, $output);
        }

        // --------------------------------------------------------------------

        // Is compression requested?
        if ($CFG->item('compress_output') === TRUE && $this->_zlib_oc == FALSE) {
            if (extension_loaded('zlib')) {
                if (isset($_SERVER['HTTP_ACCEPT_ENCODING']) AND strpos($_SERVER['HTTP_ACCEPT_ENCODING'], 'gzip') !== FALSE) {
                    ob_start('ob_gzhandler');
                }
            }
        }

        // --------------------------------------------------------------------

        // Are there any server headers to send?
        if (count($this->headers) > 0) {
            foreach ($this->headers as $header) {
                @header($header[0], $header[1]);
            }
        }

        // --------------------------------------------------------------------

        // Does the $CI object exist?
        // If not we know we are dealing with a cache file so we'll
        // simply echo out the data and exit.
        if (!isset($CI)) {
            echo $output;
            log_message('debug', "Final output sent to browser");
            log_message('debug', "Total execution time: " . $elapsed);
            return TRUE;
        }

        // --------------------------------------------------------------------

        // Do we need to generate profile data?
        // If so, load the Profile class and run it.
        if ($this->enable_profiler == TRUE) {
            $CI->load->library('profiler');

            if (!empty($this->_profiler_sections)) {
                $CI->profiler->set_sections($this->_profiler_sections);
            }

            // If the output data contains closing </body> and </html> tags
            // we will remove them and add them back after we insert the profile data
            if (preg_match("|</body>.*?</html>|is", $output)) {
                $output = preg_replace("|</body>.*?</html>|is", '', $output);
                $output .= $CI->profiler->run();
                $output .= '</body></html>';
            } else {
                $output .= $CI->profiler->run();
            }
        }

        // --------------------------------------------------------------------

        // Does the controller contain a function named _output()?
        // If so send the output there.  Otherwise, echo it.
        if (method_exists($CI, '_output')) {
            $CI->_output($output);
        } else {
            echo $output; // Send it to the browser!
        }

        log_message('debug', "Final output sent to browser");
        log_message('debug', "Total execution time: " . $elapsed);
    }

    // --------------------------------------------------------------------

    /**
     * Write a Cache File
     *
     * @access    public
     * @param    string
     * @return    void
     */
    function _write_cache($output)
    {
        $CI =& get_instance();
        $path = $CI->config->item('cache_path');

        $cache_path = ($path == '') ? APPPATH . 'cache/' : $path;

        if (!is_dir($cache_path) OR !is_really_writable($cache_path)) {
            log_message('error', "Unable to write cache file: " . $cache_path);
            return;
        }

        $uri = $CI->config->item('base_url') .
            $CI->config->item('index_page') .
            $CI->uri->uri_string();

        $cache_path .= md5($uri);

        if (!$fp = @fopen($cache_path, FOPEN_WRITE_CREATE_DESTRUCTIVE)) {
            log_message('error', "Unable to write cache file: " . $cache_path);
            return;
        }

        $expire = time() + ($this->cache_expiration * 60);

        if (flock($fp, LOCK_EX)) {
            fwrite($fp, $expire . 'TS--->' . $output);
            flock($fp, LOCK_UN);
        } else {
            log_message('error', "Unable to secure a file lock for file at: " . $cache_path);
            return;
        }
        fclose($fp);
        @chmod($cache_path, FILE_WRITE_MODE);

        log_message('debug', "Cache file written: " . $cache_path);
    }

    // --------------------------------------------------------------------

    /**
     * Update/serve a cached file
     *
     * @access    public
     * @param    object    config class
     * @param    object    uri class
     * @return    void
     */
    function _display_cache(&$CFG, &$URI)
    {
        $cache_path = ($CFG->item('cache_path') == '') ? APPPATH . 'cache/' : $CFG->item('cache_path');

        // Build the file path.  The file name is an MD5 hash of the full URI
        $uri = $CFG->item('base_url') .
            $CFG->item('index_page') .
            $URI->uri_string;

        $filepath = $cache_path . md5($uri);

        if (!@file_exists($filepath)) {
            return FALSE;
        }

        if (!$fp = @fopen($filepath, FOPEN_READ)) {
            return FALSE;
        }

        flock($fp, LOCK_SH);

        $cache = '';
        if (filesize($filepath) > 0) {
            $cache = fread($fp, filesize($filepath));
        }

        flock($fp, LOCK_UN);
        fclose($fp);

        // Strip out the embedded timestamp
        if (!preg_match("/(\d+TS--->)/", $cache, $match)) {
            return FALSE;
        }

        // Has the file expired? If so we'll delete it.
        if (time() >= trim(str_replace('TS--->', '', $match['1']))) {
            if (is_really_writable($cache_path)) {
                @unlink($filepath);
                log_message('debug', "Cache file has expired. File deleted");
                return FALSE;
            }
        }

        // Display the cache
        $this->_display(str_replace($match['0'], '', $cache));
        log_message('debug', "Cache file is current. Sending it to browser.");
        return TRUE;
    }


}
// END Output Class

/* End of file Output.php */
/* Location: ./system/core/Output.php */